package com.vivo.util;

import java.io.File;
import java.io.FileFilter;
import java.util.Enumeration;
import java.util.Hashtable;

public class MyFileFilter implements FileFilter {
		private Hashtable filters = null;
	    private String description = null;
	    private String fullDescription = null;
	    private boolean useExtensionsInDescription = true;

	    public MyFileFilter() {
	    	this.filters = new Hashtable();
	    }

	    public MyFileFilter(String extension) {
	    	this(extension,null);
	    }

	    public MyFileFilter(String extension, String description) {
			this();
			if(extension!=null) addExtension(extension);
		 	if(description!=null) setDescription(description);
	    }

	    public MyFileFilter(String[] filters) {
	    	this(filters, null);
	    }

	    public MyFileFilter(String[] filters, String description) {
			this();
			for (int i = 0; i < filters.length; i++) {
			    // add filters one by one
			    addExtension(filters[i]);
			}
		 	if(description!=null) setDescription(description);
	    }

	    public boolean accept(File f) {
			if(f != null) {
			    if(f.isDirectory()) {
				return true;
			    }
			    String extension = getExtension(f);
			    if(extension != null && filters.get(getExtension(f)) != null) {
				return true;
			    };
			}
			return false;
	    }

		public String getExtension(File f) {
			if(f != null) {
			    String filename = f.getName();
			    int i = filename.lastIndexOf('.');
			    if(i>0 && i<filename.length()-1) {
				return filename.substring(i+1).toLowerCase();
			    };
			}
			return null;
		}

	    public void addExtension(String extension) {
			if(filters == null) {
			    filters = new Hashtable(5);
			}
			filters.put(extension.toLowerCase(), this);
			fullDescription = null;
	    }

	    public String getDescription() {
			if(fullDescription == null) {
			    if(description == null || isExtensionListInDescription()) {
		 		fullDescription = description==null ? "(" : description + " (";
				// build the description from the extension list
				Enumeration extensions = filters.keys();
				if(extensions != null) {
				    fullDescription += "." + (String) extensions.nextElement();
				    while (extensions.hasMoreElements()) {
					fullDescription += ", ." + (String) extensions.nextElement();
				    }
				}
				fullDescription += ")";
			    } else {
				fullDescription = description;
			    }
			}
			return fullDescription;
	    }

	    public void setDescription(String description) {
			this.description = description;
			fullDescription = null;
	    }

	    public void setExtensionListInDescription(boolean b) {
			useExtensionsInDescription = b;
			fullDescription = null;
	    }

	    public boolean isExtensionListInDescription() {
	    	return useExtensionsInDescription;
	    }
}
